Fireproofing composition.



UNITED STATES PATENT OFFICE.

WILLIAM A. l iALL, OF NEW YORK, N. Y., ASSIGN; TO WILLIAM A. HALL LUMBER & -FIBRE CQMPANY, A CORPORATIONQF VERMONT.

FIREPROOFING COMPOSITION.

No Drawing.

To all whom it may concern:

lie it known that I, VILLIAM A. HALL,v a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented or discovered certain new and useful Improvements in Fireproofing Compositions, of which the following is a specification.

This invention 'or discovery has for its object to provide a. composition for fireproofing wood or other substances, and which will be of an efficient fireproofing character, while it will be'neutral or alkaline, and thus avoid the objections to which acid fireproofing compositions or solutions are liable. t

The tire proofing solutions now most generally in use are mixtures of phosphate of ammonia and sulfate of ammonia, both of' which are salts with acid reactions. The former is used principally for its mineralizing effect on the fiber of the Wood, in a way loading it up with inccmbustible material. The function of the sulfate of ammonia is principally for the evolution of gases which have a flame-extinguishing effect, or which do not support combustion. When the wood is exposed to a high degree of temperature in a. burning building the gases evolved from the ammonium sulfate (and to some extent from the ammonium phosphate) have a tendency to extinguish the flame of any combustible gases that may bedischarged from the wood.

Now I have discovered that sodium phosphate, preferably tri-sodium phosphate, and which is an alkaline salt, has substantially the same Function as the ammonium phosphate in that it is a very excellent mineralizer. and has marked fireproofiiig characteristics of its own. Alone it is not quite as ellicient as the ammonia phosphate, but is very much cheaper, and, being an alkali, it is more desirable for use in woods, as the woods are not materially 111] ured by alkalis, whereas they are materially m nred by acids which weaken the fiber. The ammonium sulfate is a salt with an acid reaction,

' but it can be mixed with the alkaline sodithe two in about equal proportions will pro-- Specification of Letters Patent.

Application filed November 3, 1909. Serial No. 526,028.

Patented Dec. 9. 1 913.

characteristics, whereas the acid salts lose' their efficiency, to a great extent, when heated; and heating, either by steaming or boiling, is very desirable in the fireproofing process, in order to soften the wood and make it more receptive to the fireproofing solutions.

Instead of using sulfate of ammonia in the fireproofing mixture, phosphate of ammonia might be used; but owing to the much greater cost of the latter salt the former Will preferably be employed. Also, instead. of using phosphate of soda as an al: kaline substance in the fireproofing mixture, sulfid .of'soda might be employed, but the former salt is much preferred owing to its greater efiiciency.

Having thus described my invention or discovery I claim and desire to secure by Letters Patent I 1. A fireproofing composition consisting of a salt having fireproofing properties and having an acid reactioinand a salt having an alkaline reaction, mixed together in approximately equal proportions, resultii'ig in an alkaline mixture' 2. A fireproofing composition consisting of sulfate ofammonia and trisodium phosphate, mixed together in approximately equal proportions, resulting in an alkaline mixture.

In testimony whereof I afiix my signature, in presence of two witnesses.

. \Vitnesses:

CHAS. S. HYER, C. M. SWEENEY. 

